1. Field of the Invention
This invention relates to stretchable multiple component spunbond webs and a process for preparing spunbond webs comprising filaments having high levels of crimp.
2. Description of Related Art
Nonwoven webs made from multiple component filaments are known in the art. For example, U.S. Pat. No. 5,102,724 to Okawahara et al. (Okawahara) describes a two-way stretch nonwoven fabric comprising bicomponent polyester filaments produced by conjugate spinning of side-by-side filaments of polyethylene terephthalate copolymerized with a structural unit having a metal sulfonate group and a polyethylene terephthalate or a polybutylene terephthalate.
U.S. Pat. No. 5,382,400 to Pike et al. (Pike) describes a process for making a nonwoven fabric which includes melt-spinning continuous multiple component polymeric filaments and crimping the continuous multiple component filaments for forming into a nonwoven fabric.
International Publication No. WO 00/66821 to Hancock-Cooke et al. (Hancock) describes stretchable nonwoven webs that comprise a plurality of bicomponent filaments that have been point-bonded prior to heating to develop crimp in the filaments.
U.S. Pat. No. 3,671,379 to Evans et al. (Evans) describes self-crimpable composite filaments that comprise a laterally eccentric assembly of at least two synthetic polyesters.
U.S. Pat. No. 5,750,151 to Brignola, et al. (Brignola) describes a spunbond process which includes a pair of draw rolls enclosed in a shroud. The draw rolls provide the tension required to draw the filaments near the spinneret face.
U.S. Pat. No. 4,977,611 to Maru (Maru) describes the production of spunbonded fabrics which optionally include draw rolls for imparting mechanical draw to the filaments.
While stretchable nonwoven fabrics made from multiple component filaments are known in the art, there exists a need for a method for producing uniform stretchable nonwoven fabrics from multiple component filaments which have high retractive power and which do not require a separate mechanical crimping step in order to achieve high levels of stretchability.